Resist multilayer film-attached substrate and patterning process

ABSTRACT

The present invention provides a resist multilayer film-attached substrate, including a substrate and a resist multilayer film formed on the substrate, in which the resist multilayer film has an organic resist underlayer film difficultly soluble in ammonia hydrogen peroxide water, an organic film soluble in ammonia hydrogen peroxide water, a silicon-containing resist middle layer film, and a resist upper layer film laminated on the substrate in the stated order. There can be provided a resist multilayer film-attached substrate that enables a silicon residue modified by dry etching to be easily removed in a wet manner with a removing liquid harmless to a semiconductor apparatus substrate and an organic resist underlayer film required in the patterning process, for example, an ammonia aqueous solution containing hydrogen peroxide called SC1, which is commonly used in the semiconductor manufacturing process.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a process for forming a wiring patternon a semiconductor apparatus manufacturing substrate, and a resistmultilayer film-attached substrate for use in the process.

Description of the Related Art

Conventionally, processing performance of a semiconductor apparatus hasbeen mainly improved by shortening the wavelength of a light source inlithography technology and thereby miniaturizing a pattern dimension. Inrecent years, however, an approach for shortening the wavelength of anArF light source and later one delays, and alternative methods forimproving processing performance of a semiconductor apparatus arerequired instead of the miniaturization. One proposed method is todensely arrange three-dimensional transistors, which can operate athigher speed than planar transistors, to obtain a semiconductorapparatus with high processing performance. A substrate used formanufacturing such a semiconductor apparatus (hereinafter, simplyreferred to as a substrate) has a three-dimensional structure obtainedby more complicated stepped processing than a conventional substrate.Therefore, when a pattern is formed on this substrate by a monolayerphotoresist patterning process employed for forming conventional planartransistors, a photoresist film follows a step formed during processingthe substrate, and the surface of the photoresist film is made uneven,failing to obtain a planar resist film. Thus, when the pattern is formedby exposing the photoresist to light, one cannot accurately focus on thephotoresist, which causes a reduction of substrate processing yield. Toprevent this problem, new materials and methods are required.

One solution for the problem is a multilayer resist method. This methodcan planarize a stepped substrate by an underlayer film having highplanarizing property and form a photoresist film on the planarized film,thereby increasing focus margin at exposure and preventing the reductionof substrate processing yield. Furthermore, this method allows one, whena selected underlayer film has different etching selectivity from thoseof the upper layer photoresist film and the substrate, to form a patternin the resist upper layer film, transfer the pattern to the middle layerfilm by dry etching using the resist upper layer film pattern as a dryetching mask, and further transfer the pattern to the substrate to beprocessed by dry etching using the underlayer film as a dry etchingmask.

A common multilayer resist method is a three-layer resist method, whichcan utilize a usual resist composition used in the monolayer resistmethod. For example, an organic resist underlayer film having highplanarizing property and sufficient dry etching resistance for substrateprocessing is formed on a substrate to be processed, asilicon-containing resist underlayer film is formed thereon as a middlelayer film (hereinafter, referred to as a silicon-containing resistmiddle layer film), and a photoresist film is formed thereon as a resistupper layer film. In dry etching with fluorine-based gas plasma, sincethe organic resist upper layer film has good etching selectivity ratiorelative to the silicon-containing resist middle layer film, a resistpattern can be transferred to the silicon-containing resist middle layerfilm by dry etching with fluorine-based gas plasma. In dry etching withoxygen-based gas plasma, since the silicon-containing resist middlelayer film has good etching selectivity ratio relative to the organicresist underlayer film, a silicon-containing resist middle layer filmpattern can be transferred to the organic resist underlayer film by dryetching with oxygen-based gas plasma. This method allows an organicresist underlayer film pattern having sufficient dry etching resistancefor processing to be obtained by transferring the pattern only to thesilicon-containing film even in the case of using a composition forforming a resist upper layer film that is difficult to form a patternwith a sufficient thickness for directly processing the substrate orusing a composition for forming a resist upper layer film havinginsufficient dry etching resistance for processing the substrate. Thepattern transfer by such dry etching does not cause problems such aspattern collapse due to friction of a developer during resistdevelopment, and thus an organic film pattern can be obtained with asufficient thickness to function as a dry etching mask even if theaspect ratio is high. When the organic resist underlayer film patternthus formed is used as the dry etching mask, the pattern can betransferred to a substrate having a three-dimensional transistorstructure with complicated steps. As the aforementioned organic resistunderlayer film, many materials are already known, for example, asdescribed in Patent Document 1.

Generally, the three-layer resist method requires leaving thesilicon-containing resist middle layer film several nm thick on theorganic resist underlayer film pattern to stabilize the processingdimension when the pattern is transferred to the organic resistunderlayer film by dry etching. The remaining silicon component isremoved by etching with dry etching gas for processing the substratewhen the pattern is transferred to the substrate by using the organicresist underlayer film pattern as a mask. Thus, no silicon componentremains on the organic resist underlayer film pattern after substrateprocessing. Therefore, even when the organic resist underlayer filmpattern remaining after substrate processing is dry etched (asking) orremoved in a wet manner, no silicon component remains as a residue onthe substrate.

As mentioned above, the multilayer resist method can also be applied toa substrate on which a large step is formed according to a substrateprocessing method, and thus is widely used for substrate processing. Forthis advantage, it is expected to use this method for an ionimplantation blocking mask in an ion implantation step, which is a partof a three-dimensional transistor forming process. However, an organicresist underlayer film pattern for ion implantation formed by thethree-layer resist method has a silicon component remaining thereonsince the organic resist underlayer film pattern is not used as a maskfor processing the substrate. Thus, when ions are implanted by usingthis organic resist underlayer film pattern as the blocking mask, thesilicon component remaining on the organic resist underlayer film ismodified by implanted ions, and cannot be removed together with theorganic resist underlayer film pattern in a cleaning step after theimplantation step. The component that cannot be removed finally remainson the substrate as foreign substances, reducing the yield in the ionimplantation step. To prevent this problem, the silicon componentremaining on the organic resist underlayer film pattern must beselectively cleaned and removed without affecting the organic resistunderlayer film pattern prior to the ion implantation. However, sincethe silicon component is modified by dry etching gas for transferringthe pattern to the organic resist underlayer film, the component cannotbe cleaned and removed with an ammonia aqueous solution containinghydrogen peroxide (hereinafter, referred to as ammonia hydrogen peroxidewater), which is commonly used as a harmless cleaning liquid to asubstrate in the semiconductor manufacturing process. To completelyclean and remove the modified silicon component, a hydrofluoricacid-based cleaning liquid is necessary. However, this cleaning liquidcauses damage to the surface of a semiconductor substrate, reducing theyield in the processing process. Therefore, a method that can remove thesilicon component remaining on the organic resist underlayer filmpattern without causing damage to the substrate after transferring thepattern to the organic resist underlayer film by dry etching, and amaterial that is suitable for the method are desired.

PRIOR ART DOCUMENTS Patent Documents

Patent Document 1: Japanese Unexamined Patent Application PublicationNo. 2016-094612 (US 2013/0337649 A1)

SUMMARY OF THE INVENTION

The present invention has been done to solve the above problems, and anobject thereof is to provide a resist multilayer film-attached substratethat enables a silicon residue modified by dry etching to be easilyremoved in a wet manner with a removing liquid harmless to asemiconductor apparatus substrate and an organic resist underlayer filmrequired in a patterning process, for example, an ammonia aqueoussolution containing hydrogen peroxide called SC1 (Standard Cleaner 1),which is commonly used in the semiconductor manufacturing process, andto provide a patterning process using the resist multilayerfilm-attached substrate.

To accomplish the above objects, the present invention provides a resistmultilayer film-attached substrate, comprising a substrate and a resistmultilayer film formed on the substrate,

the resist multilayer film having an organic resist underlayer filmdifficultly soluble in ammonia hydrogen peroxide water, an organic filmsoluble in ammonia hydrogen peroxide water, a silicon-containing resistmiddle layer film, and a resist upper layer film laminated on thesubstrate in the stated order.

This resist multilayer film-attached substrate enables a silicon residuemodified by dry etching to be easily removed in a wet manner with aremoving liquid harmless to a semiconductor apparatus substrate and anorganic resist underlayer film required in a patterning process, forexample, ammonia hydrogen peroxide water called SC1, which is commonlyused in the semiconductor manufacturing process.

The organic film soluble in ammonia hydrogen peroxide water ispreferably a cured product of a composition for forming an organic filmcomprising an organic solvent and a polymer compound having one or moreof repeating units shown by the following general formulae (1) to (4),

wherein R₁ represents a hydrocarbon group having 1 to 19 carbon atoms, ahalogen atom, an alkoxy group, a carboxyl group, a sulfo group, amethoxycarbonyl group, a hydroxyphenyl group, or an amino group; R₂represents a hydrogen atom or AL which is a group capable of generatingan acidic functional group by heat or acid; R₃ represents a hydrogenatom, a furanyl group, or a hydrocarbon group having 1 to 16 carbonatoms and optionally containing a chlorine atom or a nitro group; k₁,k₂, and k₃ represent 1 or 2; “l” represents 1 to 3; “m” represents 0 to3; and “n” represents 0 or 1.

Such an organic film soluble in ammonia hydrogen peroxide water(hereinafter, also simply referred to as an organic film) can be easilyremoved together with a silicon residue modified by dry etching, in awet manner with a removing liquid harmless to a semiconductor apparatussubstrate and an organic resist underlayer film required in a patterningprocess, for example, treatment with ammonia hydrogen peroxide watercalled SC1, which is commonly used in the semiconductor manufacturingprocess. When the resist multilayer film-attached substrate having suchan organic film is used for forming a pattern, an organic resistunderlayer film pattern without silicon residues can be obtained. Thisorganic resist underlayer film pattern enables substrate processing forthree-dimensional transistors with high yield.

Additionally, the organic solvent preferably contains one or morecompounds selected from propylene glycol esters, ketones, and lactones,the compounds having a total concentration of more than 30 wt % withrespect to the whole organic solvent.

When the composition for forming an organic film contains the organicsolvent satisfying the above condition, coating property of the organicfilm on the organic resist underlayer film can be improved, and theorganic film is made uniform without defects in the obtained resistmultilayer film-attached substrate.

Additionally, the composition for forming an organic film preferablyfurther comprises either or both of a thermal acid generator and acrosslinking agent.

When the composition for forming an organic film contains either or bothof a thermal acid generator and a crosslinking agent, the organic filmis formed with uniform thickness and uniform composition on the organicresist underlayer film in the obtained resist multilayer film-attachedsubstrate, and intermixing can be controlled when the silicon-containingresist middle layer film is laminated on the organic film.

Additionally, the organic film soluble in ammonia hydrogen peroxidepreferably exhibits a dissolution rate of 5 nm/min or more by treatmentwith a solution containing 29% ammonia water, 35% hydrogen peroxidewater, and water with a ratio of 1:1:8 at 65° C.

The resist multilayer film-attached substrate containing the organicfilm with such properties allows the organic film and a silicon residueon the organic film to be sufficiently removed with ammonia hydrogenperoxide water without causing damage to the semiconductor apparatusmanufacturing substrate.

Additionally, the organic film soluble in ammonia hydrogen peroxidepreferably has a thickness of 10 nm or more and less than 100 nm.

When the organic film has the above range of thickness in the inventiveresist multilayer film-attached substrate, a silicon residue can besufficiently removed, and a pattern formed in the resist upper layerfilm can be transferred while keeping the accuracy of the pattern evenwhen the pattern is transferred to the organic film and the organicresist underlayer film at once by dry etching using thesilicon-containing resist middle layer film as a dry etching mask.

Additionally, the silicon-containing resist middle layer film preferablycontains either or both of boron and phosphorus.

When the pattern is transferred to the organic film and the organicresist underlayer film at once by dry etching using thesilicon-containing resist middle layer film having a formed pattern as amask, the solubility of the silicon-containing resist middle layer filmpattern with respect to ammonia hydrogen peroxide water can be reduceddue to the structural change by gas or plasma in dry etching. However,when the silicon-containing resist middle layer film contains either orboth of boron and phosphorus, the silicon-containing resist middle layerfilm and/or the silicon residue can be made soluble in ammonia hydrogenperoxide water even after dry etching, regardless of gas and conditionsof dry etching.

Moreover, the present invention provides a patterning processcomprising:

photo-exposing the resist upper layer film of the above resistmultilayer film-attached substrate, and developing the resist upperlayer film with a developer to form a pattern in the resist upper layerfilm;

transferring the pattern to the silicon-containing resist middle layerfilm by etching using the resist upper layer film having the formedpattern as an etching mask;

transferring the pattern to the organic film and the organic resistunderlayer film by etching using the silicon-containing resist middlelayer film having the transferred pattern as an etching mask;

removing the silicon-containing resist middle layer film having thetransferred pattern and the organic film having the transferred patternby treatment with ammonia hydrogen peroxide water; and

transferring the pattern to the substrate by using the organic resistunderlayer film having the transferred pattern as a mask.

This patterning process enables a silicon residue modified by dryetching to be easily removed in a wet manner with a removing liquidharmless to a semiconductor apparatus substrate and an organic resistunderlayer film required in a patterning process, for example, ammoniahydrogen peroxide water called SC1, which is commonly used in thesemiconductor manufacturing process. Thus, an organic resist underlayerfilm pattern on which no silicon components remain can be formed.

The patterning process preferably further comprises removing the organicresist underlayer film having the transferred pattern by dry etching orwet etching after transferring the pattern to the substrate.

The inventive patterning process uses the resist multilayerfilm-attached substrate in which an organic film soluble in ammoniahydrogen peroxide water is provided between an organic resist underlayerfilm and a silicon-containing resist middle layer film formed directlyunder a photoresist film, in the three-layer resist method on asubstrate; in other words, this patterning process is substantially afour-layer resist method. This process includes forming an organicresist underlayer film on a substrate, forming an organic film solublein ammonia hydrogen peroxide water on the organic resist underlayer film(i.e., between the organic resist underlayer film and asilicon-containing resist middle layer film), forming thesilicon-containing resist middle layer film, forming a resist upperlayer film, forming a pattern in the resist upper layer film,transferring the pattern to the silicon-containing resist middle layerfilm by dry etching, and transferring the pattern to the organic filmand the organic resist underlayer film at once by dry etching using thetransferred pattern as a mask. In this process, if thesilicon-containing resist middle layer film is soluble in ammoniahydrogen peroxide water and the organic resist underlayer film isdifficultly soluble in ammonia hydrogen peroxide water, the siliconcomponents remaining on the organic resist underlayer film pattern canbe removed by ammonia hydrogen peroxide water treatment together withthe organic film. As a result, an organic resist underlayer film patternwithout a silicon residue can be formed. Use of the obtained organicresist underlayer film pattern as a mask for forming a pattern in thesubstrate prevents foreign substances from remaining on the substratewhen the organic resist underlayer film pattern is finally removed bydry etching or wet etching, and the substrate can be processed with highyield even when three-dimensional transistors having large steps areformed.

The inventive resist multilayer film-attached substrate enables asilicon residue modified by dry etching to be easily removed in a wetmanner with a removing liquid harmless to a semiconductor apparatussubstrate and an organic resist underlayer film required in a patterningprocess, for example, ammonia hydrogen peroxide water called SC1, whichis commonly used in the semiconductor manufacturing process. Thisenables formation of an organic resist underlayer film pattern on whichno silicon components remain. This pattern can be used as a mask forprocessing and patterning the substrate. Since no foreign substancesremain on the substrate after the organic resist underlayer film patternis removed by dry etching or wet etching, a reduction of the yield canbe prevented in the three-dimensional transistor manufacturing process.That is, a semiconductor apparatus having high performance can beeconomically manufactured.

Moreover, the inventive patterning process enables a silicon residuemodified by dry etching to be easily removed in a wet manner with aremoving liquid harmless to a semiconductor apparatus substrate and anorganic resist underlayer film required in a patterning process, forexample, ammonia hydrogen peroxide water called SC1, which is commonlyused in the semiconductor manufacturing process. Thus, an organic resistunderlayer film pattern on which no silicon components remain can beformed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As mentioned above, it is desired to develop a resist multilayerfilm-attached substrate and a patterning process that enable a siliconresidue modified by dry etching to be easily removed in a wet mannerwith a removing liquid harmless to a semiconductor apparatus substrateand an organic resist underlayer film required in a patterning process,for example, ammonia hydrogen peroxide water called SC1, which iscommonly used in the semiconductor manufacturing process, and canprevent foreign substances from remaining on the substrate afterprocessing.

The present inventors have earnestly investigated to achieve the aboveobject and consequently found that the problems can be solved by aresist multilayer film-attached substrate, including a substrate and aresist multilayer film formed on the substrate, in which the resistmultilayer film has an organic resist underlayer film difficultlysoluble in ammonia hydrogen peroxide water, an organic film soluble inammonia hydrogen peroxide water, a silicon-containing resist middlelayer film, and a resist upper layer film laminated on the substrate inthe stated order.

Hereinafter, embodiments of the present invention will be described, butthe present invention is not limited thereto.

[Resist Multilayer Film-Attached Substrate]

The inventive resist multilayer film-attached substrate includes asubstrate and a resist multilayer film (laminated films) formed on thesubstrate.

[Substrate]

The substrate (the substrate to be processed) in the inventive resistmultilayer film-attached substrate may be, but is not particularlylimited to, a semiconductor substrate such as a silicon substrate, aninsulating substrate such as a glass substrate, a metal substrate, or aresin substrate. In particular, the substrate may have a layer to beprocessed on its surface, preferably made of TiN, W, SiO₂, SiN, p-Si,Al, or a silica low-dielectric insulator film.

[Resist Multilayer Film]

The resist multilayer film in the inventive resist multilayerfilm-attached substrate has an organic resist underlayer filmdifficultly soluble in ammonia hydrogen peroxide water, an organic filmsoluble in ammonia hydrogen peroxide water, a silicon-containing resistmiddle layer film, and a resist upper layer film laminated on thesubstrate in the stated order. Hereinafter, each film will be described.

<Organic Resist Underlayer Film>

The resist multilayer film in the inventive resist multilayerfilm-attached substrate has an organic resist underlayer film. Theorganic resist underlayer film has resistance to ammonia hydrogenperoxide water (i.e., the film is difficultly soluble in ammoniahydrogen peroxide water). Herein, the organic resist underlayerdifficultly soluble in ammonia hydrogen peroxide water specificallyindicates a film that exhibits a dissolution rate of 3 nm/min or less bytreatment with a solution containing 29% ammonia water, 35% hydrogenperoxide water, and water with a ratio of 1:1:8 at 65° C.

Examples of the organic resist underlayer film include organic resistunderlayer films described in Japanese Unexamined Patent ApplicationPublication No. 2004-205685 (U.S. Pat. No. 7,427,464 B2), JapaneseUnexamined Patent Application Publication No. 2010-122656 (US2010/0099044 A1 and US 2013/0184404 A1), Japanese Unexamined PatentApplication Publication No. 2012-214720 (US 2012/0252218 A1), andJapanese Unexamined Patent Application Publication No. 2016-094612 (US2013/0337649 A1).

The organic resist underlayer film can be formed by applying acomposition for forming an organic resist underlayer film on a substrateto be processed by a spin coating method or the like. The spin coatingmethod allows the composition to have good filling property. After spincoating, the composition is baked to evaporate the solvent, preventmixing with a resist upper layer film and a silicon-containing resistmiddle layer film, and promote crosslinking reaction. Baking may beperformed at 100° C. or higher and 600° C. or lower, for 10 to 600seconds, preferably 10 to 300 seconds. The baking temperature is morepreferably 200° C. or higher and 500° C. or lower. Considering theeffect on device damage and wafer deformation, the upper limit of theheating temperature of wafer process in lithography is preferably 600°C. or lower, more preferably 500° C. or lower.

In the above-described method for forming the organic resist underlayerfilm, the organic resist underlayer film can be formed by applying thecomposition for forming an organic resist underlayer film on a substrateto be processed by the spin coating method or the like, and baking andcuring the composition in an atmosphere such as air, N₂, Ar, or He.Baking the composition for forming an organic resist underlayer film inan oxygen-containing atmosphere yields a cured film having resistance toammonia hydrogen peroxide water.

The above method for forming the organic resist underlayer film providesexcellent filling and planarizing properties and makes the cured filmflatten regardless of unevenness of a substrate to be processed. It isthus extremely useful for forming a planar cured film on a substratehaving a structure or a step with a height of 30 nm or more.

The thickness of the organic resist underlayer film for planarizing andmanufacturing a semiconductor apparatus is appropriately selected, andpreferably 5 to 500 nm, particularly preferably 10 to 400 nm.

<Organic Film Soluble in Ammonia Hydrogen Peroxide Water>

The resist multilayer film in the inventive resist multilayerfilm-attached substrate has an organic film soluble in ammonia hydrogenperoxide water. The organic film soluble in ammonia hydrogen peroxidewater is preferably formed from a composition for forming an organicfilm containing an organic solvent and a polymer compound having one ormore of repeating units shown by the following general formulae (1) to(4) (i.e., the film is preferably a cured product of the composition forforming an organic film),

wherein R₁ represents a hydrocarbon group having 1 to 19 carbon atoms, ahalogen atom, an alkoxy group, a carboxyl group, a sulfo group, amethoxycarbonyl group, a hydroxyphenyl group, or an amino group; R₂represents a hydrogen atom or AL which is a group capable of generatingan acidic functional group by heat or acid; R₃ represents a hydrogenatom, a furanyl group, or a hydrocarbon group having 1 to 16 carbonatoms and optionally containing a chlorine atom or a nitro group; k₁,k₂, and k₃ represent 1 or 2; “l” represents 1 to 3; “m” represents 0 to3; and “n” represents 0 or 1.

Examples of the repeating unit shown by the general formula (1) includethe following structures.

Examples of the repeating unit shown by the general formula (2) includethe following structures.

Examples of the repeating unit shown by the general formula (3) includethe following structures.

Examples of the repeating unit shown by the general formula (4) includethe following structures.

Above all, preferable repeating unit is a structure shown by the generalformula (2) or (3). The composition for forming an organic film thatcontains the polymer compound having such a repeating unit, in which acarboxyl group with high polarity is effectively positioned, can form anorganic film having excellent wet-removability in ammonia hydrogenperoxide water.

Examples of monomers that can provide the repeating units shown by thegeneral formulae (1) to (4) in which n=0 include phenol, o-cresol,m-cresol, p-cresol, 2,3-dimethylphenol, 2,5-dimethylphenol,3,4-dimethylphenol, 3,5-dimethylphenol, 2,4-dimethylphenol,2,6-dimethylphenol, 2,3,5-trimethylphenol, 3,4,5-trimethylphenol,2-t-butylphenol, 3-t-butylphenol, 4-t-butylphenol, resorcinol,2-methylresorcinol, 4-methylresorcinol, 5-methylresorcinol, catechol,4-t-butylcatechol, 2-methoxyphenol, 3-methoxyphenol, 2-propylphenol,3-propylphenol, 4-propylphenol, 2-isopropylphenol, 3-isopropylphenol,4-isopropylphenol, 2-methoxy-5-methylphenol, 2-t-butyl-5-methylphenol,4-phenylphenol, tritylphenol, pyrogallol, thymol, hydroxyphenyl glycidylether, 4-fluorophenol, 3,4-difluorophenol, 4-trifluoromethylphenol,4-chlorophenol, 4-hydroxybenzenesulfonic acid, 4-vinylphenol, and1-(4-hydroxyphenyl)naphthalene.

Examples of monomers that can provide the repeating units in which n=1include 1-naphthol, 2-naphthol, 2-methyl-1-naphthol,4-methoxy-1-naphthol, 7-methoxy-2-naphthol, 1,2-dihydroxynaphthalene,1,3-dihydroxynaphthalene, 2,3-dihydroxynaphthalene,1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene,1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene,1,7-dihydroxynaphthalene, 2,7-dihydroxynaphthalene,1,8-dihydroxynaphthalene, 5-amino-1-naphthol,2-methoxycarbonyl-1-naphthol, 6-(4-hydroxyphenyl)-2-naphthol,6-(cyclohexyl)-2-naphthol, 1,1′-bi-2,2′-naphthol, 6,6′-bi-2,2′-naphthol,9,9-bis(6-hydroxy-2-naphthyl)fluorene, 6-hydroxy-2-vinylnaphthalene,1-hydroxymethylnaphthalene, 2-hydroxymethylnaphthalene,8-hydroxynaphthalene-1-sulfonic acid, 2-hydroxynaphthalene-7-sulfonicacid, 2,3-dihydroxynaphthalene-7-sulfonic acid, and1,7-dihydroxynaphthalene-3-sulfonic acid.

These monomers may be used alone, or may be used in combination of twoor more kinds to control n-value, k-value, and etching resistance.

As a condensing agent for condensation reaction with these monomers,there may be mentioned the following aldehyde compounds: for example,formaldehyde, trioxane, paraformaldehyde, acetaldehyde, propylaldehyde,butylaldehyde, cyclopentanecarboxaldehyde, cyclopentenecarboxaldehyde,cyclohexanecarboxaldehyde, cyclohexenecarboxaldehyde,norbornanecarboxaldehyde, norbornenecarboxaldehyde,adamantanecarbaldehyde, benzaldehyde, phenylacetaldehyde,α-phenylpropylaldehyde, β-phenylpropylaldehyde, 2-hydroxybenzaldehyde,3-hydroxybenzaldehyde, 4-hydroxybenzaldehyde, 2,3-dihydroxybenzaldehyde,2,4-dihydroxybenzaldehyde, 3,4-dihydroxybenzaldehyde,2-chlorobenzaldehyde, 3-chlorobenzaldehyde, 4-chlorobenzaldehyde,2-nitrobenzaldehyde, 3-nitrobenzaldehyde, 4-nitrobenzaldehyde,2-methylbenzaldehyde, 3-methylbenzaldehyde, 4-methylbenzaldehyde,2-ethylbenzaldehyde, 3-ethylbenzaldehyde, 4-ethylbenzaldehyde,2-methoxybenzaldehyde, 3-methoxybenzaldehyde, 4-methoxybenzaldehyde,anthracenecarbaldehyde, pyrenecarbaldehyde, and furfural.

As other examples, there may be mentioned compounds shown by thefollowing formulae.

The ratio of the aldehyde compound used as the condensing agent to themonomer is preferably 0.01 to 5 mol, more preferably 0.05 to 2 mol per 1mol of the total monomer.

The proportion of the repeating unit shown by the general formulae (1)to (4) in all repeating units is preferably 10% or more, more preferably30% or more, with the whole of repeating units being 100%.

Generally, polycondensation reaction using raw materials as describedabove can be performed by using an acid or a base as a catalyst withouta solvent or in a solvent, at room temperature or, if necessary, undercooling or heating. In this manner, a polymer compound (a polymer) canbe obtained. Examples of the solvent to be used include alcohols such asmethanol, ethanol, isopropyl alcohol, butanol, ethylene glycol,propylene glycol, diethylene glycol, glycerol, methyl cellosolve, ethylcellosolve, butyl cellosolve, and propylene glycol monomethyl ether;ethers such as diethyl ether, dibutyl ether, diethylene glycol diethylether, diethylene glycol dimethyl ether, tetrahydrofuran, and1,4-dioxane; chlorinated solvents such as methylene chloride,chloroform, dichloroethane, and trichloroethylene; hydrocarbons such ashexane, heptane, benzene, toluene, xylene, and cumene; nitriles such asacetonitrile; ketones such as acetone, ethyl methyl ketone, and isobutylmethyl ketone; esters such as ethyl acetate, n-butyl acetate, andpropylene glycol methyl ether acetate; lactones such as γ-butyrolactone;and non-protic polar solvents such as dimethyl sulfoxide, N,N-dimethylformamide, and hexamethyl phosphoric triamide. These solvents may beused alone or in combination of two or more kinds. These solvents can beused in the range of 0 to 2,000 parts by mass based on 100 parts by massof the reaction raw materials.

Examples of the acid catalyst include inorganic acids such ashydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid,phosphoric acid, and heteropoly acid; organic acids such as oxalic acid,trifluoroacetic acid, methanesulfonic acid, benzenesulfonic acid,p-toluenesulfonic acid, and trifluoromethanesulfonic acid; and Lewisacids such as aluminum trichloride, aluminum ethoxide, aluminumisopropoxide, boron trifluoride, boron trichloride, boron tribromide,tin tetrachloride, tin tetrabromide, dibutyltin dichloride, dibutyltindimethoxide, dibutyltin oxide, titanium tetrachloride, titaniumtetrabromide, titanium(IV) methoxide, titanium(IV) ethoxide,titanium(IV) isopropoxide, and titanium(IV) oxide. Examples of the basecatalyst include inorganic bases such as sodium hydroxide, potassiumhydroxide, barium hydroxide, sodium carbonate, sodium hydrogencarbonate, potassium carbonate, lithium hydride, sodium hydride,potassium hydride, and calcium hydride; alkyl metals such as methyllithium, n-butyl lithium, methyl magnesium chloride, and ethyl magnesiumbromide; alkoxides such as sodium methoxide, sodium ethoxide, andpotassium t-butoxide; and organic bases such as triethyl amine,diisopropyl ethyl amine, N,N-dimethylaniline, pyridine, and4-dimethylamino pyridine. The using amount thereof is preferably 0.001to 100 wt %, preferably 0.005 to 50 wt % with respect to the rawmaterials. The reaction temperature is preferably about −50° C. toboiling point of the solvent, more preferably room temperature to 100°C.

The polycondensation reaction may be performed by charging the monomers,the condensing agent, and the catalyst all at once or by adding dropwisethe monomers and the condensing agent in the presence of the catalyst.

After completion of the polycondensation reaction, an unreacted rawmaterial, catalyst, etc., in the reaction system can be removed by asuitable method, including increasing the temperature of the reactionvessel to 130 to 230° C. at about 1 to 50 mmHg to remove volatilecomponents; adding an appropriate solvent or water to fractionate thepolymer; or dissolving the polymer in a good solvent and thenreprecipitating the polymer in a poor solvent, depending oncharacteristics of the obtained reaction product.

With respect to the molecular weight, the polymer thus obtainedpreferably has a weight average molecular weight (Mw) in terms ofpolystyrene of 500 to 500,000, particularly preferably 1,000 to 100,000.The molecular weight dispersity is preferably in the range of 1.2 to 20.When monomer components, oligomer components, or low-molecular weightcomponents having a molecular weight (Mw) of 1,000 or less are cut,volatile components can be reduced during baking so that contaminationaround a baking cup and surface defects due to drop of depositedvolatile components on a wafer can be prevented.

The composition for forming an organic film suited for forming theorganic film soluble in ammonia hydrogen peroxide water contains anorganic solvent. Illustrative examples of the organic solvent includeketones such as cyclopentanone, cyclohexanone, and methyl-2-amyl ketone;alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol,1-methoxy-2-propanol, 1-ethoxy-2-propanol, propylene glycol monomethylether, ethylene glycol monomethyl ether, propylene glycol monoethylether, and ethylene glycol monoethyl ether; ethers such as propyleneglycol dimethyl ether and diethylene glycol dimethyl ether; esters suchas propylene glycol monomethyl ether acetate, propylene glycol monoethylether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate,tert-butyl propionate, and propylene glycol mono-tert-butyl etheracetate; and γ-butyrolactone. These solvents may be used alone or incombination of two or more kinds, although the solvent is not limitedthereto.

In the organic solvent, the total concentration of one or more compoundsselected from propylene glycol esters, ketones, and lactones (forexample, one or more compounds selected from propylene glycol monomethylether acetate, cyclopentanone, cyclohexanone, methyl-2-amyl ketone, andγ-butyrolactone of the above-mentioned organic solvents) is preferablymore than 30 wt % with respect to the whole organic solvent. When theorganic solvent satisfies this requirement, a uniform organic film canbe reliably formed on the organic resist underlayer film.

To the composition for forming an organic film, an acid generator and acrosslinking agent may be added to further promote crosslinkingreaction. The acid generator can be classified into a material thatgenerates an acid by thermal decomposition (a thermal acid generator)and a material that generates an acid by light irradiation; and any acidgenerators can be added.

Examples of the acid generator include onium salts, diazomethanederivatives, glyoxime derivatives, bissulfone derivatives, sulfonateesters of N-hydroxyimide compounds, β-ketosulfone derivatives, disulfonederivatives, nitrobenzylsulfonate derivatives, sulfonates, and sulfonateester derivatives. More specifically, there may be mentioned materialsdescribed in paragraphs (0081) to (0111) of Japanese Unexamined PatentApplication Publication No. 2008-65303 (US 2008/0038662 A1).

Examples of the crosslinking agent include melamine compounds, guanaminecompounds, glycoluril compounds, or urea compounds substituted with atleast one group selected from a methylol group, an alkoxymethyl group,and an acyloxymethyl group, epoxy compounds, thioepoxy compounds,isocyanate compounds, azide compounds, and compounds having a doublebond such as an alkenyl ether group. More specifically, there may bementioned materials described in paragraphs (0074) to (0080) of JapaneseUnexamined Patent Application Publication No. 2008-65303 (US2008/0038662 A1).

Moreover, a surfactant may be added to the composition for forming anorganic film to enhance coating property in spin coating. Examples ofthe surfactant include nonionic surfactants such as polyoxyethylenealkyl ethers, polyoxyethylene alkylallyl ethers, polyoxyethylenepolyoxypropylene block copolymers, sorbitan fatty acid esters, andpolyoxyethylene sorbitan fatty acid esters, fluorinated surfactants, andpartially fluorinated oxetane ring-opening polymer surfactants. Morespecifically, there may be mentioned materials described in paragraphs(0142) to (0147) of Japanese Unexamined Patent Application PublicationNo. 2009-269953 (US 2009/0274978 A1).

Furthermore, a basic compound may be added to the composition forforming an organic film to improve storage stability. The basic compoundfunctions as a quencher for acids to prevent crosslinking reaction fromprogressing by a trace amount of acids generated from the acidgenerator. Examples of the basic compound include primary, secondary,and tertiary aliphatic amines, mixed amines, aromatic amines,heterocyclic amines, nitrogen-containing compounds having a carboxylgroup, nitrogen-containing compounds having a sulfonyl group,nitrogen-containing compounds having a hydroxyl group,nitrogen-containing compounds having a hydroxyphenyl group,nitrogen-containing alcoholic compounds, amide derivatives, and imidederivatives. More specifically, there may be mentioned materialsdescribed in paragraphs (0112) to (0119) of Japanese Unexamined PatentApplication Publication No. 2008-65303 (US 2008/0038662 A1).

The composition for forming an organic film as described above can besuitably used for forming the organic film soluble in ammonia hydrogenperoxide water provided directly under a silicon-containing resistmiddle layer film and on an organic resist underlayer film difficultlysoluble in ammonia hydrogen peroxide water.

The organic film preferably exhibits a dissolution rate of 5 nm/min ormore by treatment with a solution containing 29% ammonia water, 35%hydrogen peroxide water, and water with a ratio of 1:1:8 at 65° C. so asto be removed together with a silicon residue modified by dry etching ina wet manner.

Moreover, the organic film preferably has a thickness of 10 nm or moreand less than 100 nm, more preferably 20 nm or more and 80 nm or less.When the thickness of the organic film is 10 nm or more, siliconcomponents can be sufficiently removed by wet treatment. When thethickness is less than 100 nm, side etching can be prevented at dryetching processing, and failure does not occur during processing.

The organic film can be formed, for example, by applying the compositionfor forming an organic film on a substrate to be processed by the spincoating method or the like. After spin coating, the composition is bakedto evaporate the solvent, prevent mixing with a resist upper layer filmand a silicon-containing resist middle layer film, or promotecrosslinking reaction. Baking may be performed at 100° C. or higher and400° C. or lower, for 10 to 600 seconds, preferably 10 to 300 seconds.The baking temperature is more preferably 150° C. or higher and 350° C.or lower.

<Silicon-Containing Resist Middle Layer Film>

The resist multilayer film in the inventive resist multilayerfilm-attached substrate has a silicon-containing resist middle layerfilm. The silicon-containing resist middle layer film is preferablysoluble in ammonia hydrogen peroxide water, and can be dissolved in orremoved with ammonia hydrogen peroxide water. For example,silicon-containing resist underlayer films described in JapaneseUnexamined Patent Application Publication No. 2010-085912 (US2010/0086870 A1), Japanese Unexamined Patent Application Publication No.2010-085893 (US 2010/0086872 A1), Japanese Unexamined Patent ApplicationPublication No. 2015-028145 (US 2015/0004791 A1), WO 2010/068336 (US2011/0233489 A1), Japanese Unexamined Patent Application Publication No.2016-074772 (US 2016/0096977 A1), and Japanese Unexamined PatentApplication Publication No. 2016-074774 (US 2016/0096978 A1) arepreferably used as the silicon-containing resist middle layer film inthe present invention. Above all, films containing either or both ofboron and phosphorus have excellent wet-removability in ammonia hydrogenperoxide water and thus are particularly preferable.

<Resist Upper Layer Film>

The resist multilayer film in the inventive resist multilayerfilm-attached substrate has a resist upper layer film. The resist upperlayer film is not particularly limited, and may be appropriatelyselected depending on a patterning process. For example, whenlithography is carried out with light having a wavelength of 300 nm orless or EUV light, a chemically amplified photoresist film may be usedas the resist upper layer film. Examples of such a photoresist filminclude a film capable of forming a positive pattern by dissolving anexposed portion with an alkaline developer after photo-exposure, and afilm capable of forming a negative pattern by dissolving an unexposedportion with an organic solvent developer.

When ArF excimer laser light is used as the light having a wavelength of300 nm or less for lithography, any resist film generally used for ArFexcimer laser light can be used as the resist upper layer film. As acomposition that can provide the resist film for ArF excimer laser, manycandidates are already known. Such compositions can be mainly classifiedinto a poly(meth)acrylic type, a COMA (Cyclo Olefin Maleic Anhydride)type, a COMA-(meth)acrylic hybrid type, an ROMP (Ring Opening MetathesisPolymerization) type, a polynorbornene type, etc. Among them, the resistcomposition using a poly(meth)acrylic resin is preferably used, for ithas etching resistance attributable to an alicyclic skeleton introducedinto its side chain, and has more excellent resolution performance thanother types of resins.

The resist upper layer film can be formed by the spin coating method orthe like. The thickness of the resist upper layer film may beappropriately selected, and is preferably 20 to 500 nm, particularlypreferably 30 to 400 nm.

The resist multilayer film-attached substrate as described above enablesthe organic film and a silicon residue modified by dry etching to beeasily removed together in a wet manner with a removing liquid harmlessto a semiconductor apparatus substrate and an organic resist underlayerfilm required in a patterning process, for example, ammonia hydrogenperoxide water called SC1, which is commonly used in the semiconductormanufacturing process. When an organic resist underlayer patternobtained from this substrate is removed by dry etching or wet etchingafter substrate processing, foreign substances can be prevented fromremaining on the substrate. Consequently, a reduction of the yield canbe prevented in the three-dimensional transistor manufacturing process,and a semiconductor apparatus having high performance can beeconomically manufactured.

(Patterning Process)

The present invention provides a patterning process using the aboveresist multilayer film-attached substrate. The inventive patterningprocess includes photo-exposing the resist upper layer film of the aboveresist multilayer film-attached substrate, and developing the resistupper layer film with a developer to form a pattern in the resist upperlayer film; transferring the pattern to the silicon-containing resistmiddle layer film by etching using the resist upper layer film havingthe formed pattern as an etching mask; transferring the pattern to theorganic film and the organic resist underlayer film by etching using thesilicon-containing resist middle layer film having the transferredpattern as an etching mask; removing the silicon-containing resistmiddle layer film having the transferred pattern and the organic filmhaving the transferred pattern by treatment with ammonia hydrogenperoxide water; and transferring the pattern to the substrate by usingthe organic resist underlayer film having the transferred pattern as amask.

The process preferably further includes removing the organic resistunderlayer film having the transferred pattern by dry etching or wetetching after transferring the pattern to the substrate.

In the inventive patterning process, first, the resist upper layer filmof the inventive resist multilayer film-attached substrate isphoto-exposed and developed with a developer to form a pattern in theresist upper layer film. As described above, the resist upper layer filmmay be a positive type or a negative type, and any common photoresistcomposition can be used. When the resist upper layer film is formed byusing a photoresist composition, the spin coating method is preferablyused.

In case that the photoresist composition is pre-baked after spincoating, the pre-baking is preferably performed at 60 to 180° C. for 10to 300 seconds. Then, exposure, post exposure bake (PEB), anddevelopment are performed according to usual methods to obtain a resistpattern. The thickness of the resist upper layer film is preferably, butis not particularly limited to, 20 to 500 nm, more preferably 30 to 400nm. The exposure light may be a high energy beam having a wavelength of300 nm or less, specifically, an excimer laser at 248 nm or 193 nm, anextreme ultraviolet ray at 13.5 nm, an electron beam, an X-ray, or thelike.

Then, the pattern is transferred to the silicon-containing resist middlelayer film by dry etching using the obtained resist upper layer filmpattern as an etching mask. The dry etching is preferably performedwith, for example, a CF-based gas such as CF₄ or CHF₃, although it isnot particularly limited thereto.

Then, the pattern is transferred to the organic film soluble in ammoniahydrogen peroxide water and the organic resist underlayer film at onceby etching using the silicon-containing resist middle layer pattern asan etching mask. The dry etching is preferably performed with, forexample, N₂/H₂ or O₂, although it is not particularly limited thereto.

Further, the remaining silicon-containing resist middle layer filmpattern and the organic film pattern are removed together in a wetmanner. In this step, a removing liquid containing hydrogen peroxide ispreferably used. More preferably, an acid or an alkali is added to theremoving liquid to adjust pH and promote the removal. Examples of the pHadjuster (the acid or the alkali) include inorganic acids such ashydrochloric acid and sulfuric acid, organic acids such as acetic acid,oxalic acid, tartaric acid, citric acid, and lactic acid,nitrogen-containing alkalis such as ammonia, ethanolamine, andtetramethylammonium hydroxide, and nitrogen-containing organic acidcompounds such as EDTA (ethylenediamine tetraacetic acid). Inparticular, ammonia is preferable. That is, the removing liquid ispreferably ammonia hydrogen peroxide water.

When ammonia hydrogen peroxide water is used as the removing liquid, theratio of ammonia, hydrogen peroxide, and dilution deionized water is asfollows: ammonia is 0.01 to 20 parts by mass, preferably 0.05 to 15parts by mass, more preferably 0.1 to 10 parts by mass, and hydrogenperoxide is 0.01 to 20 parts by mass, preferably 0.05 to 15 parts bymass, more preferably 0.1 to 10 parts by mass, based on 100 parts bymass of deionized water.

The treatment with ammonia hydrogen peroxide water can be performed bypreparing a removing liquid of 0° C. to 80° C., preferably 5° C. to 70°C., and soaking a silicon wafer having a target substrate to beprocessed in the removing liquid. If necessary, the removing liquid maybe sprayed on the surface, or the removing liquid may be applied whilerotating the wafer according to a usual method to easily remove thesilicon-containing resist middle layer film and the organic film solublein ammonia hydrogen peroxide water together.

After the treatment with ammonia hydrogen peroxide water, the amount ofthe removed silicon components is preferably checked by quantifyingsilicon remaining on the surface of the organic resist underlayer film.For example, analysis can be carried out by a method described inJapanese Unexamined Patent Application Publication No. 2016-177262 (US2016/0276152 A1).

Then, the pattern is transferred to the substrate by using the organicresist underlayer film pattern thus obtained as a mask (substrateprocessing). The inventive patterning process can be suitably employedfor substrate processing without dry etching, for example, implantationprocessing using various ions or substrate processing by wet etching.When the substrate to be processed is made of TiN, W, or the like, andthus can be etched with ammonia hydrogen peroxide water, the substratecan be processed as a silicon residue and the organic film are removedtogether with ammonia hydrogen peroxide water. Moreover, the substratecan also be processed by dry etching; for example, the substrate to beprocessed made of SiO₂, SiN, or a silica low-dielectric insulator filmcan be etched mainly with fluorocarbon gas; p-Si, Al, or W mainly with achlorine- or bromine-based gas.

After substrate processing, the organic resist underlayer film patternused as the mask may be removed by dry etching or wet etching. Dryetching (asking) condition is not particularly limited; for example,N₂/H₂ gas or O₂ gas is preferably used as the organic resist underlayerfilm is processed. Wet etching condition is also not particularlylimited; for example, there may be mentioned wet treatment with sulfuricacid and hydrogen peroxide. The inventive patterning process can preventforeign substances from remaining on the substrate after removing theorganic resist underlayer film pattern.

As described above, in the inventive patterning process, an organicresist underlayer film is formed on a substrate, an organic film solublein ammonia hydrogen peroxide water is formed on the organic resistunderlayer film, a silicon-containing resist middle layer film isformed, and a resist upper layer film is formed to obtain a resistmultilayer film-attached substrate, and then a pattern is formed in theresist upper layer film, the pattern is transferred to thesilicon-containing resist middle layer film by dry etching, and thepattern is transferred to the organic film and the organic resistunderlayer film at once by dry etching using the transferred pattern asa mask. As described above, silicon components remaining on thetransferred pattern can be removed by ammonia hydrogen peroxide watertogether with the organic film, whereby an organic resist underlayerfilm pattern without silicon residues can be obtained. This organicresist underlayer film pattern can be used as a mask for processing thesubstrate, and can prevent foreign substances from remaining on thesubstrate when the pattern is finally removed by dry etching or wetetching. Consequently, the substrate can be processed with high yieldeven when three-dimensional transistors having large steps are formed.

EXAMPLES

Hereinafter, the present invention will be specifically described withreference to Synthesis Examples, Examples, and Comparative Example, butthe present invention is not limited thereto. In the following examples,% means mass %, and molecular weight was measured by GPC. In GPCmeasurement, detection was performed by RI using tetrahydrofuran as aneluent, and molecular weight was determined in terms of polystyrene.

Synthesis of Polymer Compound Synthesis Example (A1)

A 500-mL three-necked flask was charged with 40.00 g (0.36 mol) ofresorcinol, 10.00 g of a PGME solution containing 20 mass %p-toluenesulfonic acid monohydrate, and 72.00 g of 2-methoxy-1-propanol,and the mixture was heated to 80° C. under stirring. 23.59 g of 37%formalin (0.29 mol of formaldehyde) was added thereto, followed bystirring for 11 hours. The reaction solution was then mixed with 160 gof ultrapure water and 200 g of ethyl acetate, transferred to aseparation funnel, and washed with 150 g of ultrapure water 10 times toremove the acid catalyst and metal impurities. The obtained organiclayer was condensed under reduced pressure to be 76 g, ethyl acetate wasadded thereto to form 150 g of a solution, and 217 g of n-hexane wasadded to the solution. Consequently, the n-hexane layer and thehigh-concentration polymer solution were respectively separated into anupper layer and a lower layer, and the upper layer was removed. The sameoperation was repeated twice, and the obtained polymer solution wascondensed and dried under reduced pressure at 80° C. for 13 hours toobtain Polymer compound A1. GPC measurement showed that the compound hada weight average molecular weight (Mw) of 800 and a dispersity (Mw/Mn)of 1.3. Polymer compound A1 had the repeating unit shown by the generalformula (4).

Synthesis Example (A2)

A 1,000-mL three-necked flask was charged with 80.1 g (0.50 mol) of1,5-dihydroxynaphthalene, 26.4 g (0.24 mol) of a 37% formalin solution,and 250 g of 2-methoxy-1-propanol in a nitrogen atmosphere to form ahomogeneous solution with a liquid temperature of 80° C. To the solutionwas gently added 18 g of a 2-methoxy-1-propanol solution containing 20%p-toluenesulfonic acid, and the mixture was stirred at 110° C. for 12hours. After cooling to room temperature, 500 g of methyl isobutylketone was added, and the organic layer was washed with 200 g of purewater 5 times and then evaporated under reduced pressure to dryness.Then, 300 mL of THF was added to the residue, and a polymer wasprecipitated by 2,000 mL of hexane. The precipitated polymer wascollected by filtration and dried under reduced pressure to obtainPolymer compound A2. GPC measurement showed that the compound had aweight average molecular weight (Mw) of 3,000 and a dispersity (Mw/Mn)of 2.7. Polymer compound A2 had the repeating unit shown by the generalformula (4).

Synthesis Example (A3)

A 2,000-mL three-necked flask was charged with 80.1 g (0.50 mol) of1,5-dihydroxynaphthalene, 100.1 g (0.40 mol) of3,4-di-t-butoxybenzaldehyde, and 600 g of 2-methoxy-1-propanol in anitrogen atmosphere to form a homogeneous solution with a liquidtemperature of 80° C. To the solution was gently added 6.4 g of a 25%sodium hydroxide aqueous solution, and the mixture was stirred at 110°C. for 24 hours. After cooling to room temperature, 1,500 g of ethylacetate was added, and the organic layer was washed with 300 g of a 3%nitric acid aqueous solution, further washed with 300 g of pure water 5times, and then evaporated under reduced pressure to dryness. Then, 400mL of THF was added to the residue, and a polymer was precipitated by3,000 mL of hexane. The precipitated polymer was collected by filtrationand dried under reduced pressure to obtain Polymer compound A3. GPCmeasurement showed that the compound had a weight average molecularweight (Mw) of 2,900 and a dispersity (Mw/Mn) of 2.9. Polymer compoundA3 had the repeating unit shown by the general formula (1).

Synthesis Example (A4)

A 1,000-mL flask was charged with 80 g (0.50 mol) of1,5-dihydroxynaphthalene, 36.6 g (0.30 mol) of 4-hydroxybenzaldehyde,and 145 g of methyl cellosolve. Then, 20 g of a methyl cellosolvesolution containing 20 mass % p-toluenesulfonic acid was added theretounder stirring at 70° C. The solution was then heated to 85° C. andstirred for 6 hours. After cooling to room temperature, the solution wasdiluted with 800 mL of ethyl acetate. The solution was then transferredto a separation funnel, and repeatedly washed with 200 mL of deionizedwater to remove the reaction catalyst and metal impurities. After theobtained solution was condensed under reduced pressure, 600 mL of ethylacetate was added to the residue, and a polymer was precipitated by2,400 mL of hexane. The precipitated polymer was collected by filtrationand dried under reduced pressure to obtain Polymer compound A4. GPCmeasurement showed that the compound had a weight average molecularweight (Mw) of 3,800 and a dispersity (Mw/Mn) of 2.4. Polymer compoundA4 had the repeating unit shown by the general formula (1).

Synthesis Example (A5)

A 2,000-mL three-necked flask was charged with 80.1 g (0.50 mol) of2,7-dihydroxynaphthalene, 100.1 g (0.40 mol) of t-butylterephthalaldehydate, and 600 g of 2-methoxy-1-propanol in a nitrogenatmosphere to form a homogeneous solution with a liquid temperature of80° C. To the solution was gently added 6.4 g of a 25% sodium hydroxideaqueous solution, and the mixture was stirred at 110° C. for 24 hours.After cooling to room temperature, 1,500 g of ethyl acetate was added,and the organic layer was washed with 300 g of a 3% nitric acid aqueoussolution, further washed with 300 g of pure water 5 times, and thenevaporated under reduced pressure to dryness. Then, 400 mL of THF wasadded to the residue, and a polymer was precipitated by 3,000 mL ofhexane. The precipitated polymer was collected by filtration and driedunder reduced pressure to obtain Polymer compound A5. GPC measurementshowed that the compound had a weight average molecular weight (Mw) of2,900 and a dispersity (Mw/Mn) of 2.9. Polymer compound A5 had therepeating unit shown by the general formula (2).

Synthesis Example (A6)

A 2,000-mL three-necked flask was charged with 94.4 g (0.50 mol) of6-hydroxy-2-naphthoic acid, 100.1 g (0.40 mol) of t-butylterephthalaldehydate, and 600 g of 2-methoxy-1-propanol in a nitrogenatmosphere to form a homogeneous solution with a liquid temperature of80° C. To the solution was gently added 6.4 g of a 25% sodium hydroxideaqueous solution, and the mixture was stirred at 110° C. for 24 hours.After cooling to room temperature, 1,500 g of ethyl acetate was added,and the organic layer was washed with 300 g of a 3% nitric acid aqueoussolution, further washed with 300 g of pure water 5 times, and thenevaporated under reduced pressure to dryness. Then, 400 mL of THF wasadded to the residue, and a polymer was precipitated by 3,000 mL ofhexane. The precipitated polymer was collected by filtration and driedunder reduced pressure to obtain Polymer compound A6. GPC measurementshowed that the compound had a weight average molecular weight (Mw) of3,500 and a dispersity (Mw/Mn) of 2.8. Polymer compound A6 had therepeating unit shown by the general formula (2).

Synthesis Example (A7)

A 2,000-mL three-necked flask was charged with 80.1 g (0.50 mol) of1,5-dihydroxynaphthalene, 60.1 g (0.40 mol) of terephthalaldehydic acid,and 600 g of 2-methoxy-1-propanol in a nitrogen atmosphere to form ahomogeneous solution with a liquid temperature of 80° C. To the solutionwas gently added 6.4 g of a 25% sodium hydroxide aqueous solution, andthe mixture was stirred at 110° C. for 24 hours. After cooling to roomtemperature, 1,500 g of ethyl acetate was added, and the organic layerwas washed with 300 g of a 3% nitric acid aqueous solution, furtherwashed with 300 g of pure water 5 times, and then evaporated underreduced pressure to dryness. Then, 400 mL of THF was added to theresidue, and a polymer was precipitated by 3,000 mL of hexane. Theprecipitated polymer was collected by filtration and dried under reducedpressure to obtain Polymer compound A7. GPC measurement showed that thecompound had a weight average molecular weight (Mw) of 2,200 and adispersity (Mw/Mn) of 2.9. Polymer compound A7 had the repeating unitshown by the general formula (2).

Synthesis Example (A8)

A 200-mL three-necked flask was charged with 9.4 g (0.05 mol) of6-hydroxy-2-naphthoic acid, 5.3 g (0.05 mol) of terephthalaldehydicacid, and 60 g of 2-methoxy-1-propanol in a nitrogen atmosphere to forma homogeneous solution with a liquid temperature of 80° C. To thesolution was gently added 0.6 g of a 25% sodium hydroxide aqueoussolution, and the mixture was stirred at 110° C. for 24 hours. Aftercooling to room temperature, 150 g of ethyl acetate was added, and theorganic layer was washed with 30 g of a 3% nitric acid aqueous solution,further washed with 30 g of pure water 5 times, and then evaporatedunder reduced pressure to dryness. Then, 40 mL of THF was added to theresidue, and a polymer was precipitated by 300 mL of hexane. Theprecipitated polymer was collected by filtration and dried under reducedpressure to obtain Polymer compound A8. GPC measurement showed that thecompound had a weight average molecular weight (Mw) of 2,000 and adispersity (Mw/Mn) of 2.6. Polymer compound A8 had the repeating unitshown by the general formula (2).

Synthesis Example (A9)

A 2,000-mL three-necked flask was charged with 54.1 g (0.50 mol) ofo-cresol, 140.2 g (0.40 mol) of3,4-bis(t-butoxycarbonylmethoxy)benzaldehyde, and 600 g of2-methoxy-1-propanol in a nitrogen atmosphere to form a homogeneoussolution with a liquid temperature of 80° C. To the solution was gentlyadded 6.4 g of a 25% sodium hydroxide aqueous solution, and the mixturewas stirred at 110° C. for 24 hours. After cooling to room temperature,1,500 g of ethyl acetate was added, and the organic layer was washedwith 300 g of a 3% nitric acid aqueous solution, further washed with 300g of pure water 5 times, and then evaporated under reduced pressure todryness. Then, 400 mL of THF was added to the residue, and a polymer wasprecipitated by 3,000 mL of hexane. The precipitated polymer wascollected by filtration and dried under reduced pressure to obtainPolymer compound A9. GPC measurement showed that the compound had aweight average molecular weight (Mw) of 3,200 and a dispersity (Mw/Mn)of 3.0. Polymer compound A9 had the repeating unit shown by the generalformula (3).

Synthesis Example (A10)

A 2,000-mL three-necked flask was charged with 80.1 g (0.50 mol) of1,6-dihydroxynaphthalene, 94.5 g (0.40 mol) of4-t-butoxycarbonylmethoxybenzaldehyde, and 600 g of 2-methoxy-1-propanolin a nitrogen atmosphere to form a homogeneous solution with a liquidtemperature of 80° C. To the solution was gently added 6.4 g of a 25%sodium hydroxide aqueous solution, and the mixture was stirred at 110°C. for 24 hours. After cooling to room temperature, 1,500 g of ethylacetate was added, and the organic layer was washed with 300 g of a 3%nitric acid aqueous solution, further washed with 300 g of pure water 5times, and then evaporated under reduced pressure to dryness. Then, 400mL of THF was added to the residue, and a polymer was precipitated by3,000 mL of hexane. The precipitated polymer was collected by filtrationand dried under reduced pressure to obtain Polymer compound A10. GPCmeasurement showed that the compound had a weight average molecularweight (Mw) of 2,700 and a dispersity (Mw/Mn) of 2.7. Polymer compoundA10 had the repeating unit shown by the general formula (3).

[Preparation of Composition for Forming Organic Film (Sols. 1 to 22)]

Polymer compounds A1 to A10 and additives, namely, crosslinking agentsXL1 to 3, thermal acid generator AG1, and an organic solvent containing0.1 mass % FC-4430 (available from Sumitomo 3M Ltd.) as a surfactantwere mixed in a proportion shown in Table 1, and filtered through a0.1-μm filter made of fluorinated resin to prepare compositions forforming an organic film (Sols. 1 to 22). Sols. 1 to 10, 15 to 16, and 20to 22 are compositions for forming an organic film to provide a resistmultilayer film-attached substrate according to the present invention,whereas Sols. 11 to 14 and 17 to 19 are comparative compositions forforming an organic film. Table 1 also shows the total amount of one ormore compounds selected from propylene glycol esters, ketones, andlactones in the whole organic solvent in the prepared composition forforming an organic film.

TABLE 1 Total amount of Additive propylene glycol Polymer Thermal acidCrosslinking ester, ketone, and compound generator agent Organic lactonein whole (part by (part by (part by solvent (part organic solvent No.mass) mass) mass) by mass) (wt %) Sol. 1 A1 AG1 XL1 PGMEA 100 (100) (2)(10) (1600) Sol. 2 A2 AG1 XL1 PGMEA/Cyho 100 (100) (2) (10) (1100/500)Sol. 3 A3 AG1 XL2 PGMEA 100 (100) (2) (10) (1600) Sol. 4 A4 PGMEA/PGEE31.3 (100) (500/1100) Sol. 5 A5 AG1 PGMEA/GBL 100 (100) (2) (1100/500)Sol. 6 A6 AG1 XL3 PGMEA 100 (100) (2) (10) (1600) Sol. 7 A7 AG1PGMEA/PGEE 31.3 (100) (2) (500/1100) Sol. 8 A8 AG1 XL2 PGMEA/PGEE 31.3(100) (2) (10) (500/1100) Sol. 9 A9 AG1 PGMEA/PGEE 31.3 (100) (2)(500/1100) Sol. 10 A10 AG1 PGMEA/PGEE 31.3 (100) (2) (500/1100) Sol. 11A4 PGMEA/4M2P 10 (100) (160/1440) Sol. 12 A4 PGMEA/4M2P 20 (100)(320/1280) Sol. 13 A4 PGMEA/4M2P 25 (100) (400/1200) Sol. 14 A4PGMEA/4M2P 30 (100) (480/1120) Sol. 15 A4 PGMEA/4M2P 40 (100) (640/960)Sol. 16 A4 PGMEA/4M2P 60 (100) (960/640) Sol. 17 A2 AG1 XL1 PGEE 0 (100)(2) (10) (1600) Sol. 18 A4 4M2P 0 (100) (1600) Sol. 19 A7 AG1 4M2P 0(100) (2) (1600) Sol. 20 A2 AG1 XL1 PGMEA 100 (100) (2) (10) (3920) Sol.21 A2 AG1 XL1 PGMEA 100 (100) (2) (10) (390) Sol. 22 A2 AG1 XL1 PGMEA100 (100) (2) (10) (260)

Thermal acid generator AG1 and crosslinking agents XL1 to 3 are shownbelow.

The organic solvents in Table 1 are as follows.

PGMEA: propylene glycol methyl ether acetate

Cyho: cyclohexanone

PGEE: propylene glycol ethyl ether

GBL: γ-butyrolactone

4M2P: 4-methyl-2-pentanol

[Solvent Resistance Evaluation]

On the organic film in the inventive resist multilayer film-attachedsubstrate, a silicon-containing resist middle layer film is formed byspin coating. Thus, resistance to an organic solvent was evaluated todetermine whether the formed organic film causes intermixing. Thecompositions for forming an organic film (Sols. 1 to 22) were eachapplied on a silicon substrate and baked at 285° C. for 60 seconds toform an organic film, and thickness T1 was measured. Then, a solvent(PGMEA/PGME=30/70 (mass ratio)) was applied on the obtained organic filmby spin coating, and baked at 100° C. for 30 seconds, and thickness T2was measured. From these measurement results, the reduction in thicknessexpressed by T1-T2 was calculated. The result is given in Table 2.

TABLE 2 Film thickness Composition after baking at Film thickness forforming 285° C. after rinsing T1 − T2 organic film T1 (nm) T2 (nm) (nm)Sol. 1 24.9 24.8 0.1 Sol. 2 25.4 25.4 0.0 Sol. 3 25.0 24.9 0.1 Sol. 425.3 25.1 0.2 Sol. 5 25.3 25.3 0.0 Sol. 6 25.3 25.3 0.0 Sol. 7 25.1 25.3−0.2 Sol. 8 24.9 24.8 0.1 Sol. 9 25.0 25.1 −0.1 Sol. 10 24.7 24.7 0.0Sol. 15 25.3 25.1 −0.2 Sol. 16 25.2 25.1 −0.1 Sol. 20 9.8 9.9 0.1 Sol.21 100.3 100.1 −0.2 Sol. 22 150.2 150.1 −0.1 Sol. 11 25.0 25.0 0.0 Sol.12 24.9 25.0 −0.1 Sol. 13 25.0 25.1 −0.1 Sol. 14 25.1 25.0 −0.1 Sol. 1725.1 25.2 −0.1 Sol. 18 25.0 24.7 0.3 Sol. 19 25.3 25.5 −0.2

As shown in Table 2, the organic films formed from Sols. 1 to 10, 15 to16, and 20 to 22 had sufficient organic solvent resistance. Thisindicates that these organic films allow a silicon-containing resistmiddle layer film to be formed thereon by spin coating withoutintermixing.

[Evaluation of Film Formation on Organic Resist Underlayer Film]

The organic film in the inventive resist multilayer film-attachedsubstrate is laminated on the organic resist underlayer film. Thus, thefilm forming property on the organic resist underlayer film wasdetermined. Spin-on carbon film ODL-102, available from Shin-EtsuChemical Co., Ltd., was formed with a thickness of 200 nm on a siliconwafer as an organic resist underlayer film. The composition for formingan organic film (Sols. 1 to 22) was applied thereon and baked at 285° C.for 60 seconds to form an organic film, and the film-forming conditionof the organic film was observed. The result is given in Table 3.

TABLE 3 Composition for forming organic film Film formation Sol. 1 nofilm formation failure Sol. 2 no film formation failure Sol. 3 no filmformation failure Sol. 4 no film formation failure Sol. 5 no filmformation failure Sol. 6 no film formation failure Sol. 7 no filmformation failure Sol. 8 no film formation failure Sol. 9 no filmformation failure Sol. 10 no film formation failure Sol. 15 no filmformation failure Sol. 16 no film formation failure Sol. 20 no filmformation failure Sol. 21 no film formation failure Sol. 22 no filmformation failure Sol. 11 film formation failure occurs due torepellence Sol. 12 film formation failure occurs due to repellence Sol.13 film formation failure occurs due to repellence Sol. 14 filmformation failure occurs due to repellence Sol. 17 film formationfailure occurs due to repellence Sol. 18 film formation failure occursdue to repellence Sol. 19 film formation failure occurs due torepellence

As shown in Table 3, Sols. 1 to 10, 15 to 16, and 20 to 22 could form afilm on the organic resist underlayer film by spin coating without filmformation failure. By contrast, Sols. 11 to 14 and 17 to 19 containing70 wt % or more of an alcoholic organic solvent could not form a film onthe organic resist underlayer film due to repellence.

[Wet-Removability of Organic Film with Ammonia Hydrogen Peroxide Water]

The compositions for forming an organic film (Sols. 1 to 10 and 15 to16) were each applied on a silicon substrate and baked at 285° C. for 60seconds such that an organic film was formed with a thickness of 25 nm,and thickness T1 was measured. This film was soaked in 65° C. of ammoniahydrogen peroxide water in which 29% ammonia water, 35% hydrogenperoxide water, and water have been mixed with a ratio of 1:1:8 for 5minutes. The film was then washed with pure water and dried by heatingat 100° C. for 60 seconds, and thickness T3 was measured. Moreover, thefilm removal rate was determined. The result is given in Table 4.

TABLE 4 Film thickness after treatment Film thickness with ammonia FilmComposition after baking at hydrogen peroxide removal for forming 285°C. water rate organic film T1 (nm) T3 (nm) (nm/min) Sol. 1 24.9 noresidual film ≥5 Sol. 2 25.4 no residual film ≥5 Sol. 3 25.0 no residualfilm ≥5 Sol. 4 25.3 no residual film ≥5 Sol. 5 25.3 no residual film ≥5Sol. 6 25.3 no residual film ≥5 Sol. 7 25.1 no residual film ≥5 Sol. 824.9 no residual film ≥5 Sol. 9 25.0 no residual film ≥5 Sol. 10 24.7 noresidual film ≥5 Sol. 15 25.3 no residual film ≥5 Sol. 16 25.2 noresidual film ≥5

As shown in Table 4, the organic films formed from Sols. 1 to 10 and 15to 16 could be removed with ammonia hydrogen peroxide water at a rate of5 nm/min or more.

Manufacture of Resist Multilayer Film-Attached Substrate and Evaluationof Residue after Asking of Organic Resist Underlayer Film Examples 1 to15 and Comparative Example 1

Spin-on carbon film ODL-102, available from Shin-Etsu Chemical Co.,Ltd., was formed with a thickness of 200 nm on a silicon wafer as anorganic resist underlayer film. The composition for forming an organicfilm (Sols. 1 to 10, 15 to 16, and 20 to 22) was applied thereon andbaked at 285° C. for 60 seconds to form an organic film. On the otherhand, as described above, since Sols. 11 to 14 and 17 to 19 could notform a film on the organic resist underlayer film due to repellence(i.e., a resist multilayer film-attached substrate according to thepresent invention could not be manufactured), the organic film was notintroduced in Comparative Example 1.

Then, a composition for forming a silicon-containing resist middle layerfilm (SiARC-1) shown in Table 5 was applied thereon and baked at 220° C.for 60 seconds to form a silicon-containing resist middle layer filmwith a thickness of 35 nm. An ArF resist solution for positivedevelopment (PR-1) shown in Table 6 was applied thereon and baked at110° C. for 60 seconds to form a photoresist film with a thickness of100 nm. In this manner, a resist multilayer film-attached substrate wasobtained. Further, a liquid immersion top coat composition (TC-1) shownin Table 7 was applied on the photoresist film and baked at 90° C. for60 seconds to form a top coat with a thickness of 50 nm.

Subsequently, the wafer was exposed with an ArF liquid immersionexposure apparatus (NSR-S610C manufactured by Nikon Corporation, NA:1.30, σ: 0.98/0.65, 35° polarized dipole illumination, 6% halftone phaseshift mask), baked at 100° C. for 60 seconds (PEB), developed with a2.38% tetramethylammonium hydroxide (TMAH) aqueous solution for 30seconds to form a 160 nm 1:1 positive line and space pattern. Withrespect to the wafer thus obtained, the cross-sectional shape of thepattern was observed with an electron microscope (S-4800) manufacturedby Hitachi, Ltd., and pattern collapse was observed with an electronmicroscope (CG4000) manufactured by Hitachi High-TechnologiesCorporation.

The wafer with the photoresist pattern was then dry etched undertreatment conditions shown in Table 8 and Table 9, with an etchingapparatus Telius, manufactured by Tokyo Electron Ltd., to process thesilicon-containing resist middle layer film and the organic resistunderlayer film. Moreover, the cross-sectional shape of the pattern ofthe obtained wafer was observed with an electron microscope (S-9380)manufactured by Hitachi, Ltd.

Then, the wafer was treated with 65° C. of ammonia hydrogen peroxidewater in which 29% ammonia water, 35% hydrogen peroxide water, and waterhave been mixed with a ratio of 1:1:8 for 5 minutes to remove thesilicon-containing resist middle layer film remaining after processingthe organic resist underlayer film in a wet manner. After treatment, thewafer was washed with pure water and dried by heating at 100° C. for 60seconds. Moreover, the surface of the organic resist underlayer film wasexamined by XPS analysis with K-ALPHA manufactured by Thermo FisherScientific K.K., and silicon on the organic resist underlayer film wasquantified to check whether the silicon component was removed withammonia hydrogen peroxide water.

The organic resist underlayer film pattern obtained by the aboveprocedures was processed under conditions shown in Table 10 with anetching apparatus Telius, manufactured by Tokyo Electron Ltd., and aresidual organic resist underlayer film was removed by ashing. The waferafter ashing was observed with an electron microscope (CG4000)manufactured by Hitachi High-Technologies Corporation to check thepresence or absence of residues. The result is given in Table 11.

Components of the composition for forming a silicon-containing resistmiddle layer film (SiARC-1) are shown in Table 5.

TABLE 5 Solvent Polymer Additive (part by No. (part by mass) (part bymass) mass) SiARC-1 SiARC polymer 1 (4.0) TPSNO₃ (0.02) PGEE (310) SiARCpolymer 2 (0.2) Maleic acid (0.04) Water (65) D-sorbitol (0.5) TPSNO₃:triphenylsulfonium nitrate

The molecular weight and structural formula of SiARC polymer 1 shown inTable 5 are shown below.

SiARC polymer 1: Molecular weight (Mw)=2,800

The molecular weight and structural formula of SiARC polymer 2 shown inTable 5 are shown below.

SiARC polymer 2: Molecular weight (Mw)=2,800

Components of the ArF resist solution for positive development (PR-1)are shown in Table 6.

TABLE 6 Polymer Acid generator Base Solvent No. (part by mass) (part bymass) (part by mass) (part by mass) PR-1 ArF resist PAG 1 Quencher PGMEApolymer 1 (7.0) (1.0) (2,500) (100)

The molecular weight, dispersity, and structural formula of ArF resistpolymer 1 shown in Table 6 are shown below.

ArF resist polymer 1: Molecular weight (Mw)=7,800

-   -   Dispersity (Mw/Mn)=1.78

The structural formula of the acid generator PAG1 shown in Table 6 isshown below.

The structural formula of the base Quencher shown in Table 6 is shownbelow.

Components of the liquid immersion top coat composition (TC-1) used forpatterning test by positive development are shown in Table 7.

TABLE 7 Polymer Organic solvent (part by mass) (part by mass) TC-1 Topcoat polymer Diisoamyl ether (2700) (100) 2-Methyl-1-butanol (270)

The molecular weight, dispersity, and structural formula of the top coatpolymer shown in Table 7 are shown below.

Top coat polymer: Molecular weight (Mw)=8,800

-   -   Dispersity (Mw/Mn)=1.69

Dry etching processing conditions of the silicon-containing resistmiddle layer film are shown in Table 8.

TABLE 8 Chamber pressure 10 Pa RF power 200 W CF₄ gas flow rate 50mL/min CHF₃ gas flow rate 50 mL/min N₂ gas flow rate 100 mL/min Time 20seconds

Dry etching processing conditions of the organic resist underlayer filmare shown in Table 9.

TABLE 9 Chamber pressure 2.7 Pa RF power 1000 W N₂ gas flow rate 500mL/min H₂ gas flow rate 30 mL/min Time 60 seconds

Ashing removal conditions of the organic resist underlayer film areshown in Table 10.

TABLE 10 Chamber pressure 2.7 Pa RF power 1000 W N₂ gas flow rate 500mL/min H₂ gas flow rate 30 mL/min Time 180 seconds

Table 11 shows the observation results of cross-sectional shape andpattern collapse of the photoresist pattern, the observation results ofcross-sectional shape of the pattern after dry etching processing, theresidual silicon amount on the surface of the organic resist underlayerfilm after treatment with ammonia hydrogen peroxide water, and thepresence or absence of residues after asking of the organic resistunderlayer film pattern obtained in the above evaluation.

TABLE 11 Si amount on surface of organic resist Residue CompositionThickness of Observation after underlayer film after ashing for organicfilm photoresist development Pattern after treatment of organic formingafter baking Pattern sectional with ammonia resist organic at 285° C.Sectional Pattern shape after hydrogen peroxide underlayer film (nm)Shape collapse dry etching water (atomic %) film pattern Example 1 Sol.1 24.9 rectangular no collapse rectangular not detected no residueExample 2 Sol. 2 25.4 rectangular no collapse rectangular not detectedno residue Example 3 Sol. 3 25.0 rectangular no collapse rectangular notdetected no residue Example 4 Sol. 4 25.3 rectangular no collapserectangular not detected no residue Example 5 Sol. 5 25.3 rectangular nocollapse rectangular not detected no residue Example 6 Sol. 6 25.3rectangular no collapse rectangular not detected no residue Example 7Sol. 7 25.1 rectangular no collapse rectangular not detected no residueExample 8 Sol. 8 24.9 rectangular no collapse rectangular not detectedno residue Example 9 Sol. 9 25.0 rectangular no collapse rectangular notdetected no residue Example Sol. 10 24.7 rectangular no collapserectangular not detected no residue 10 Example Sol. 15 25.3 rectangularno collapse rectangular not detected no residue 11 Example Sol. 16 25.2rectangular no collapse rectangular not detected no residue 12 ExampleSol. 20 9.8 rectangular no collapse rectangular not detected no residue13 Example Sol. 21 100.3 rectangular no collapse rectangular notdetected no residue 14 Example Sol. 22 150.2 rectangular no collapseside not detected no residue 15 etching Comparative none 0.0 rectangularno collapse rectangular 7.2 residue was example 1 found

As shown in Table 11, in Examples 1 to 12 introducing the organic filmformed from Sols. 1 to 10 and 15 to 16, which can be removed withammonia hydrogen peroxide water, no silicon remained on the organicresist underlayer film after treatment with ammonia hydrogen peroxidewater, and no residue was caused after asking of the organic resistunderlayer film pattern. Referring to the effect on the thickness of theorganic film in Examples 13 to 15 and Comparative example 1, as shown inExample 13, when the organic film was thin, no silicon residue was foundon the surface of the organic resist underlayer film after treatmentwith ammonia hydrogen peroxide water, and no residue was caused afterashing of the organic resist underlayer film pattern. Moreover, as shownin Example 15, when the film was thick, although side etching wasobserved on a part of the organic film at dry etching, no residue wascaused after ashing of the organic resist underlayer film pattern. Bycontrast, as shown in Comparative example 1, when the organic film wasnot used, the silicon residue could not be removed, and a residue wascaused after ashing of the organic resist underlayer film pattern.

The above results demonstrated the following. The inventive resistmultilayer film-attached substrate has an organic film that can beeasily removed, together with a silicon residue modified by dry etching,in a wet manner with a removing liquid harmless to a semiconductorapparatus substrate and an organic resist underlayer film required inthe patterning process, and can be used as a material for an ionimplantation blocking mask used for forming three-dimensionaltransistors. In particular, use of the organic film having a thicknessof 10 nm or more and less than 100 nm reliably enables a processingprocess without residues. This can prevent a reduction of the yield inthe three-dimensional transistor manufacturing process and enableseconomical manufacture of a semiconductor apparatus with highperformance.

It should be noted that the present invention is not limited to theforegoing embodiment. The embodiment is just an exemplification, and anyexamples that have substantially the same feature and demonstrate thesame functions and effects as those in the technical concept describedin claims of the present invention are included in the technical scopeof the present invention.

What is claimed is:
 1. A resist multilayer film-attached substrate,comprising a substrate and a resist multilayer film formed on thesubstrate, the resist multilayer film having an organic resistunderlayer film insoluble in ammonium hydrogen-peroxide mixture, anorganic film soluble in ammonium hydrogen-peroxide mixture, asilicon-containing resist middle layer film, and a resist upper layerfilm laminated on the substrate in the stated order.
 2. The resistmultilayer film-attached substrate according to claim 1, wherein theorganic film soluble in ammonium hydrogen-peroxide mixture is a curedproduct of a composition for forming an organic film comprising anorganic solvent and a polymer compound having one or more of repeatingunits shown by the following general formulae (1) to (4),

wherein R₁ represents a hydrocarbon group having 1 to 19 carbon atoms, ahalogen atom, an alkoxy group, a carboxyl group, a sulfo group, amethoxycarbonyl group, a hydroxyphenyl group, or an amino group; R₂represents a hydrogen atom or AL which is a group capable of generatingan acidic functional group by heat or acid; R₃ represents a hydrogenatom, a furanyl group, or a hydrocarbon group having 1 to 16 carbonatoms and optionally containing a chlorine atom or a nitro group; k₁,k₂, and k₃ represent 1 or 2; “l” represents 1 to 3; “m” represents 0 to3; and “n” represents 0 or
 1. 3. The resist multilayer film-attachedsubstrate according to claim 1, wherein the organic film soluble inammonium hydrogen-peroxide mixture is a cured product of a compositionfor forming an organic film comprising an organic solvent which containsone or more compounds selected from propylene glycol esters, ketones,and lactones, the compounds having a total concentration of more than 30wt % with respect to the whole organic solvent, and a polymer compoundhaving one or more of repeating units shown by the following generalformulae (1) to (4),

wherein R₁ represents a hydrocarbon group having 1 to 19 carbon atoms, ahalogen atom, an alkoxy group, a carboxyl group, a sulfo group, amethoxycarbonyl group, a hydroxyphenyl group, or an amino group; R₂represents a hydrogen atom or AL which is a group capable of generatingan acidic functional group by heat or acid; R₃ represents a hydrogenatom, a furanyl group, or a hydrocarbon group having 1 to 16 carbonatoms and optionally containing a chlorine atom or a nitro group; k₁, k₂and k₃ represent 1 or 2; “l” represents 1 to 3; “m” represents 0 to 3;and “n” represents 0 or
 1. 4. The resist multilayer film-attachedsubstrate according to claim 1, wherein the organic film soluble inammonium hydrogen-peroxide mixture is a cured product of a compositionfor forming an organic film comprising an organic solvent, a polymercompound having one or more of repeating units shown by the followinggeneral formulae (1) to (4), and further either or both of a thermalacid generator and a crosslinking agent,

wherein R₁ represents a hydrocarbon group having 1 to 19 carbon atoms, ahalogen atom, an alkoxy group, a carboxyl group, a sulfo group, amethoxycarbonyl group, a hydroxyphenyl group, or an amino group; R₂represents a hydrogen atom or AL which is a group capable of generatingan acidic functional group by heat or acid; R₃ represents a hydrogenatom, a furanyl group, or a hydrocarbon group having 1 to 16 carbonatoms and optionally containing a chlorine atom or a nitro group; k₁, k₂and k₃ represent 1 or 2; “l” represents 1 to 3; “m” represents 0 to 3;and “n” represents 0 or
 1. 5. The resist multilayer film-attachedsubstrate according to claim 1, wherein the organic film soluble inammonium hydrogen-peroxide mixture is a cured product of a compositionfor forming an organic film comprising an organic solvent which containsone or more compounds selected from propylene glycol esters, ketones,and lactones, the compounds having a total concentration of more than 30wt % with respect to the whole organic solvent, a polymer compoundhaving one or more of repeating units shown by the following generalformulae (1) to (4), and further, either or both of a thermal acidgenerator and a crosslinking agent,

wherein R₁ represents a hydrocarbon group having 1 to 19 carbon atoms, ahalogen atom, an alkoxy group, a carboxyl group, a sulfo group, amethoxycarbonyl group, a hydroxyphenyl group, or an amino group; R₂represents a hydrogen atom or AL which is a group capable of generatingan acidic functional group by heat or acid; R₃ represents a hydrogenatom, a furanyl group, or a hydrocarbon group having 1 to 16 carbonatoms and optionally containing a chlorine atom or a nitro group; k₁, k₂and k₃ represent 1 or 2; “l” represents 1 to 3; “m” represents 0 to 3;and “n” represents 0 or
 1. 6. The resist multilayer film-attachedsubstrate according to claim 1, wherein the organic film soluble inammonium hydrogen-peroxide mixture exhibits a dissolution rate of 5nm/min or more by treatment with a solution containing 29% ammoniawater, 35% hydrogen peroxide water, and water with a ratio of 1:1:8 at65° C.
 7. The resist multilayer film-attached substrate according toclaim 2, wherein the organic film soluble in ammonium hydrogen-peroxidemixture exhibits a dissolution rate of 5 nm/min or more by treatmentwith a solution containing 29% ammonia water, 35% hydrogen peroxidewater, and water with a ratio of 1:1:8 at 65° C.
 8. The resistmultilayer film-attached substrate according to claim 3, wherein theorganic film soluble in ammonium hydrogen-peroxide mixture exhibits adissolution rate of 5 nm/min or more by treatment with a solutioncontaining 29% ammonia water, 35% hydrogen peroxide water, and waterwith a ratio of 1:1:8 at 65° C.
 9. The resist multilayer film-attachedsubstrate according to claim 4, wherein the organic film soluble inammonium hydrogen-peroxide mixture exhibits a dissolution rate of 5nm/min or more by treatment with a solution containing 29% ammoniawater, 35% hydrogen peroxide water, and water with a ratio of 1:1:8 at65° C.
 10. The resist multilayer film-attached substrate according toclaim 5, wherein the organic film soluble in ammonium hydrogen-peroxidemixture exhibits a dissolution rate of 5 nm/min or more by treatmentwith a solution containing 29% ammonia water, 35% hydrogen peroxidewater, and water with a ratio of 1:1:8 at 65° C.
 11. The resistmultilayer film-attached substrate according to claim 1, wherein theorganic film soluble in ammonium hydrogen-peroxide mixture has athickness of 10 nm or more and less than 100 nm.
 12. The resistmultilayer film-attached substrate according to claim 2, wherein theorganic film soluble in ammonium hydrogen-peroxide mixture has athickness of 10 nm or more and less than 100 nm.
 13. The resistmultilayer film-attached substrate according to claim 3, wherein theorganic film soluble in ammonium hydrogen-peroxide mixture has athickness of 10 nm or more and less than 100 nm.
 14. The resistmultilayer film-attached substrate according to claim 1, wherein thesilicon-containing resist middle layer film contains either or both ofboron and phosphorus.
 15. The resist multilayer film-attached substrateaccording to claim 2, wherein the silicon-containing resist middle layerfilm contains either or both of boron and phosphorus.
 16. The resistmultilayer film-attached substrate according to claim 3, wherein thesilicon-containing resist middle layer film contains either or both ofboron and phosphorus.
 17. A patterning process comprising:photo-exposing the resist upper layer film of the resist multilayerfilm-attached substrate according to claim 1, and developing the resistupper layer film with a developer to form a pattern in the resist upperlayer film; transferring the pattern to the silicon-containing resistmiddle layer film by etching using the resist upper layer film havingthe formed pattern as an etching mask; transferring the pattern to theorganic film and the organic resist underlayer film by etching using thesilicon-containing resist middle layer film having the transferredpattern as an etching mask; removing the silicon-containing resistmiddle layer film having the transferred pattern and the organic filmhaving the transferred pattern by treatment with ammoniumhydrogen-peroxide mixture; and transferring the pattern to the substrateby using the organic resist underlayer film having the transferredpattern as a mask.
 18. A patterning process comprising: photo-exposingthe resist upper layer film of the resist multilayer film-attachedsubstrate according to claim 2, and developing the resist upper layerfilm with a developer to form a pattern in the resist upper layer film;transferring the pattern to the silicon-containing resist middle layerfilm by etching using the resist upper layer film having the formedpattern as an etching mask; transferring the pattern to the organic filmand the organic resist underlayer film by etching using thesilicon-containing resist middle layer film having the transferredpattern as an etching mask; removing the silicon-containing resistmiddle layer film having the transferred pattern and the organic filmhaving the transferred pattern by treatment with ammoniumhydrogen-peroxide mixture; and transferring the pattern to the substrateby using the organic resist underlayer film having the transferredpattern as a mask.
 19. A patterning process comprising: photo-exposingthe resist upper layer film of the resist multilayer film-attachedsubstrate according to claim 3, and developing the resist upper layerfilm with a developer to form a pattern in the resist upper layer film;transferring the pattern to the silicon-containing resist middle layerfilm by etching using the resist upper layer film having the formedpattern as an etching mask; transferring the pattern to the organic filmand the organic resist underlayer film by etching using thesilicon-containing resist middle layer film having the transferredpattern as an etching mask; removing the silicon-containing resistmiddle layer film having the transferred pattern and the organic filmhaving the transferred pattern by treatment with ammoniumhydrogen-peroxide mixture; and transferring the pattern to the substrateby using the organic resist underlayer film having the transferredpattern as a mask.
 20. The patterning process according to claim 17,further comprising removing the organic resist underlayer film havingthe transferred pattern by dry etching or wet etching after transferringthe pattern to the substrate.